Radio transmission system



Oct. 27, 1931. w. E. BRANCH RADIO TRANSMISS ION SYSTEM Filed Jan. 3. 1930 2 Sheets-Sheet 1 INVE NTOR. W; E. BRANCH, BY 8 .3 H1455 .suPPLY 6 A TTORNE Y.

Oct. 27, 1931. w. 1;. BRANCH 1,828,920

RADIO TRANSMISSION SYSTEM Filed Jan. 5. 1930 2 Sheets-Sheet 2 INVENTOR.

-W. E.BRANCH,

A TTORNE Y.

Patented Oct. 27, 1931 UNITED STATES WILIiIAM ELLISON BRANCH, OF, FOR-T WORTH, TEXAS RADIO TRANSMISSION SYSTEM' 7 Application filed January 3, 1930. Serial No. 418,387.

My invention relates to power supply systems in general, and more specifically to power supply systems for energizing radio transmitters employing thermionic tubes.

' One object of my invention is to provide 2 ciated with a source of electrical energy and a load circuit whereby said load circuit is automatically short circuited when said source and said load circuit are disconnected.

A better understanding can be had of the circuit breakers and power supply systems of my invention by referring to the specification followingand to the accompanying drawings, wherein:

Figure ltis a schematic circuit diagram showing the power supply system and circuit breaker for radio transmitters and Fig. 2 is a side elevation showing the circuit breaker employed in the power supply system of my invention.

In power supply systems for energizing the anodes of thermionic tubes employed in radio transmitters it is often necessary to employ some type of circuit breaker in the circuit. In transmitters employing alternating current and a rectifier, it is customary to employ circuit breakers or switches both before and after the rectifier unit. The circuit including the transformer and source of energy associated with the input circuit may be asgociated with a circuit breaker, the circuit betweentherectifier andthe thermionic tubes or load circuit is associated with a circuit breaker or both circuits are associated with individual circuit breakers. These breakers may be manually operated or automatically operated. The manually or hand operated t pe breaker is suitable for many purposes ut does not respond to an overload condition escaping the attention of the attending operator. The automatic type of circuit breaker usually employs a solenoid designed to actuate the releasing latch of the movable arm when an overload or un derload condition arises. The latter type of circuit breaker may be hand op'eratedif so desired.

Fig. 1 of the accompanying drawings is a schematic circuit diagram. showing a space radio broadcasting system in its entirety. Thermionic tubes 1, 2, 3 and 4 are employed in speechamplifier, modulator, oscillator and power amplifier circuits respectively. The cathode circuits of thermionic tubes 1, 2, 3 and 4 are energized from source 6. The control electrodes of thermionic tubes 1, 2, 3 and 4 are supplied with biasing energy from .70 source 7.

I The anode supply energy for thermionic tubes 1,2, 3 and 4 is derived from source 8. Source 8 may comprise three phase alternatmg current. Source 8 is associated with transformers 9, 10 and 11, which transformers supply the high voltage to be rectified and caused to energize the anodes of tubes 1, 2,. 3 and 4. Transformers 12, 13 and 14 are employed to ener ize the cathode circuits of mercury arc rectifier tubes 15, 16 and 17, respectively. These transformers supply what is generally referred to as the keep alive potential. The secondary. windings of transformers 9, 10, 11, 12,13 and 14 are 55 provided with center connections which are electrically connected in series. Tubes 15, 16 and 17 are of the ordinarydesign. An exhausted glass vessel has a plurality of electrodes sealedtherein. A pool of mercury constitutes the cathode. Two of the above mentioned electrodes of each tube constitute the anodes which are connected to the secondary terminals of the transformers. Reactances 18, 19 and 20 are connected in series with the center taps of transformer secondaries associated with tubes 15,, 16 and 17 respectively. The last mentioned center taps constitute the cathode connections from rectifier tubes 15, 16 and 17 and are elec- 1 is completed by contact member 28.

trically connected with the center taps of transformers 9, and 11. The center tap of transformer 11 constitutes the negative side of the high potential rectified current, the center connection on the secondary of transformer 12 constituting the positive side of the high potential rectified current. Should the switches in any one of the primary circuits of transformers 9, 10 and 11 be opened, the output potential of the rectifier system would be reduced since the output of each unit of the rectifier system is connected in series with the output of the others. Tubes 15, 16 and 17 are immersed in oil and adapted to be mechanically rocked to start operation. The rectified energy passes through suitable reactances 21, 22 and 23 which serve to smooth out the fluctuations of current.

Capacities 2'4, 25 and 26 are employed for 'a similar purpose serving to store the energy and to deliver the same to the associated circuit in such a manner as to cause the resultant energy to be substantially free from fluctuations. Reactan'ces 21, 22 and 23 and capacities 24, 25 and 26 constitute a filter circuit designed to eliminate the fluctuations which design depends upon the frequency of source 8. The rectified energy is associated with a horn gap comprising members 34 and 35. Horn gap 3435 is designed to draw out any are arising from an overload condition. The circuit breakerin its entirety comprises gap members 34-35, contact members 28 and 29, armature 33, spring 32,armature and electromagnet 31. An armature 33 is pivoted to the common base member and carries suitable contact members adapted to contact with member 28 or 29. Spring 32 returns armature 33 to the position occupied when contacting with member 29, the normally open position. A'latchmember 33a is carried by armature 33 and is adapted to engage with latch member 30 when armature 33 is in the closed position. Spring 30a causes latch members 30 and 33a to remain engaged when armature 33 is moved to the closed position. Electromagnet 31 is positioned adjacent to armature 30 and adapted to exert a force of attraction sufficient to cause members 30 and 33a to become disengaged. Electromagnet 31 is of the proper design to cause such action of armature 33 when and only when the winding is energized by a predetermined value of'current. The winding of electromagnet 31 is connected in series with the source of anode supply potential to thermionic tubes 1, 2, 3 and 4. The energization of electromagnet 31 depends upon the closing of armature 33 whereby the electrical circuit The closing of armature 33 may be manually, electrically or mechanicallycontrolled. Ground 27 is connected to contact member 29 and'to the cathode'circuits of thermionic tubes 1, 2, 3 and 4. Thenegative terminal from rectitiers 15, 16, 17 is likewise connected to ground 27.

The operation of the circuit breaker and power supply system of my invention can best be understood by referring to Fig. 1. Mercury arc rectifier tubes 15, 16 and 17 are energized and caused to rectify the energy from source 8. The rectified energy is liltered by choke coils 21, 22 and 23 and capacities 24, 25 and 26. Sources 6 and 7 are caused to supply the cathode and biasing energy to thermionic tubes 1, 2, 3 and 4. Armature 33 is closed to the position whereby contact member 28 completes the circuit through armature 33 to electromagnet 31 and to the anodes of thermionic tubes 1, 2, 3 and 4. Because of spring 30a armature 33 is retained in the closed position under normal operational conditions. The supply of anode potential to thermionic tubes 1, 2, 3 and 4 energizes electromagnet 31. This energization is, however, not suflicient to cause the actuation of armature 30a. Should the current supplied the anode circuits of thermionic tubes 1, 2, 3 and 4 rise to an abnormal value, the energization of armature 30a would be suiiicient to release latch member 33a and hence to allow armature 33 to return to the normally opened position. This causes a low resistance shunt across the anode cathode circuit of thermionic tubes 1, 2, 3 and 4 by means of contact member 29, armature 33, electromagnet 31 and ground 27.

Fig. 2 of the accompanying drawings is a diagrammatic illustration showing one form of the circuit breaker of my invention. This breaker is of the direct control type although the same may be actuated by remote means without departing from the spirit of my i11- vention. A swinging arm or armature 33 carries contact members 2964. Armature 33 is actuated by handle 38 and toggle-joint mechanism 39. Contact 28 is supported by laminated metal spring 28a. Spring member 2860 is electrically connected to metallic rod 35. Metallic rod member 34 car 'ies contact member 29 which contacts with contact memher 290. when armature 33 is in the opened position. The mechanism in its entirety may be mounted on a suitable base 40 of slate, phenol compositions or the like. This type of circuit breaker requires the attention of the attendant and hence is called non-automatic. A solenoid may be associated with the tog le mechanism 39 for causing automatic operation when an overload condition arises.

Many modifications are possible without departing from the spirit of my invention. In Fig. 1 of the accompanying drawings, the wires a and b may be interchanged. To supply potential of proper polarity to the anode circuits of thermionic tubes 1, 2, 3 and 4 the interchanging of wires a and b necessitates also the interchanging of wires 0 and (Z.

This arrangement causes the potential of armature 33 to be the same as ground potential. In the arrangement shown in Fig. 2 the ground connection may be to either movable arm 33, gap member 34 or gap member 35. Many different designs of circuit breakers may be employed including the types that operate in oil or air and special designs for different classes of service. The circuit breaker of my invention may be designed to carry the required load and the parts properly spaced to avoid potential breakdown. The circuit arrangement shown in Fig. 1 of the accompanying drawings is merely representative and for the purpose of illustration. It is to be understood that the embodiments of my invention are not to be limited by the foregoing specification or by the accompanying drawings but only as defined by the scope of the appended claims.

hat I claim as new and desire to secure by Letters Patent of the United States is as 7 follows 1. A power supply system for radio transmitters comprising in combination a source of electrical energy, a circuit breaker associated with said source and with said radio transmitter, said circuit breaker being provided with contact members adapted to short 1/ circuit the power circuits of said radio transmitter when said source is disassociated therewith.

2. A power supply system for radio transmitters comprising in combination a source of electrical energy, a circuit breaker associated with said source and with said radio transmitter, said circuit breaker being provided with contact members adapted to simultaneously short circuit the power circuits of said radio transmitter when said source 1S disassociated therewith.

3. A power supply system comprising in combination a source of electrical energy, a load circuit, a circuit breaker interposed between said source and said load circuit and said circuit breaker provided with auxiliary contact members adapted to substantially short circuit said load circuit when said circuit breaker is opened.

4. A power supply system comprising in combination a source of electrical energy, a load circuit, a circuit breaker interposed between said source and said load circuit and said circuit breaker provided with auxiliary contact members adapted to simultaneously short circuit said load circuit when said circuit breaker is opened.

5. A power supply system comprising in combination a source of electrical energy, a circuit breaker connected in series with said source and terminals adapted to be associated with a load circuit and means for simultaneously connecting a low resistance shunt across said terminals when said circuit breaker is open circuited.

6. In a power supply system the combination source of electrical energy, a load cir cuit, a circuit breaker adapted to associate said source with said load circuit and said circuit breaker adapted to connect a low resistance shunt across said load circuit when said circuit breaker is opened.

7. In a high frequency transmitter employing thermionic tubes having anodes adapted to be energized by a source of electrical energy the combination of a circuit breaker associated with said source adapted to substan tially short circuit said anodes and their respective cathodes when said source is disconnected from said transmitter.

8. In a high frequency transmitter employing thermionic tubes having anodes adapted to be energized by a source of electrical energy the combination of a circuit breaker associated with said source adapted to simultaneously short circuit said anodes and their respective cathodes when said source is disconnected from said transmitter.

9. In a supply circuit for energizing the anodes of thermionic tubes the combination of a circuit breaker adapted to connect a relatively low resistance across the anode-cathode circuits of said tubes when the energizing potential is removed from said anodes.

10. In a supply circuit for energizing the anodes of thermionic tubes the combination of a. circuit breaker adapted to simultaneously connect a relatively low resistance across the anode-cathode circuits of said tubes when the energizing potential is removed from said anodes.

11. In a power supply system for energizing the anodes of thermionic tubes the combination of a source of alternating current,

a mercury arc rectifier, connected with said source, a relatively low resistance path, and an overload circuit breaker connected with the output of said rectifier and said thermionic tubes, said circuit breaker being adapted to simultaneously connect said relatively low resistance path across the anode-cathode circuits of said tubes when said circuit breaker is opened.

In testimony whereof I aflix my signature.

WILLIAM ELLISON BRANCH. 

